Charge state characterization of dangling bond circuitry on hydrogen passivated silicon

With current CMOS technologies approaching their performance limits, nanoscale atomic electronics are poised to provide the next-generation of devices and a continuation of Moore's law. Several promising beyond-CMOS platforms, such as dangling bond (DB) circuitry on hydrogen-passivated silicon require precise knowledge of the location of charges within fabricated atomic structures. To achieve this, atomic force microscopy (AFM) measurements are used to determine the electron population of specific dangling bonds. A key consideration for improving this ability is to ensure that the proximity of the AFM probe does not perturb the ground state charge occupation of circuit elements under investigation. Here, we directly compare AFM measurements with a minimally-perturbative scanning tunneling microscope charge sensing scheme to better establish the optimal parameter space for ground state charge measurements. To achieve this, a DB wire was sequentially legthened near a sensor DB, which allowed for the electronic detection of nearby changes of charge with single electron sensitivity. The same structures were also then investigated and compared with standard AFM characterization techniques and these results will be used to improve the charge characterization of DB structures.